LAUSR

Summary Adaptive Mesh Refinement (AMR) shows attractive properties in automatically refining the flow region of interest, and with AMR better prediction can be obtained with much less labour work and cost compared to manually re-meshing or the global mesh refinement. Cartesian AMR is well established; however, AMR on hybrid unstructured mesh which is heavily employed in the high-Reynolds number flow simulation, is less matured and existing methods may result in degraded mesh quality, which mostly happens in the boundary layer or near the sharp geometric features. User intervention or additional constraints, such as freezing all boundary layer elements or refining the whole boundary layer, are required to assist the refinement process. In this work, a novel AMR strategy is developed to handle existing difficulties. In the new method, high-order unstructured elements are first generated based on the baseline mesh; then the refinement is conducted in the parametric space; at last the mesh suitable for the solver is output. Generating refined elements in the parametric space with high-order elements is the key of this method and this helps to guarantee both the accuracy and robustness. With the current method, three-dimensional hybrid unstructured mesh of huge size and complex geometry can be automatically refined, without user intervention nor additional constraints. With test cases including the two-dimensional airfoil and three-dimensional full aircraft, the current AMR method proves to be accurate, simple and robust. This article is protected by copyright. All rights reserved.